Social interactions and olfactory cues are required for contagious itch in mice.

The phenomenon of contagious itch, observed in both humans and rodents, remains a topic of ongoing debate concerning its modulators and underlying pathways. This study delves into the relationship between contagious itch and familiar olfactory cues, a non-visual factor contributing to this intriguing behavior. Our findings showed that contagious itch in observer mice occurs during physical interaction with the cagemate itch-demonstrator but not with a stranger demonstrator or in a non-physical encounter condition. Notably, itch-experienced observer mice displayed an increased contagious itch behavior, highlighting the relevance of itch-associated memory in this phenomenon. Furthermore, anosmic observer mice, whether itch-naïve or itch-experienced, displayed no contagious itch behavior. These results demonstrate that the familiar olfactory cues, specifically cagemate body odors, are required for contagious itch behaviors in mice. In line with these behavioral findings, our study reveals increased activity in brain regions associated with olfaction, emotion, and memory during contagious itch, including the olfactory bulb, the amygdala, the hypothalamus, and the hippocampus, with this activity diminished in anosmic mice. In conclusion, our study unveils the critical role of familiar olfactory cues in driving contagious itch in mice, shedding light on the interplay between social factors, sensory perception, and memory in this phenomenon.

LRRK2; Communicative Role in the Treatment of Parkinson's Disease and Ulcerative Colitis Overlapping.

BACKGROUND: Involvement of gastrointestinal inflammation in Parkinson's disease (PD) pathogenesis and movement have progressively emerged. Inflammation is involved in the etiology of both PD and inflammatory bowel disease (IBD). Transformations in leucine-rich recurrent kinase 2 (LRRK2) are among the best hereditary supporters of IBD and PD. Elevated levels of LRRK2 have been reported in stimulated colonic tissue from IBD patients and peripheral invulnerable cells from irregular PD patients; thus, it is thought that LRRK2 directs inflammatory cycles. OBJECTIVE: Since its revelation, LRRK2 has been seriously linked in neurons, albeit various lines of proof affirmed that LRRK2 is profoundly communicated in invulnerable cells. Subsequently, LRRK2 might sit at a junction by which stomach inflammation and higher LRRK2 levels in IBD might be a biomarker of expanded risk for inconsistent PD or potentially may address a manageable helpful objective in incendiary sicknesses that increment the risk of PD. Here, we discuss how PD and IBD share covering aggregates, especially regarding LRRK2 and present inhibitors, which could be a helpful objective in ongoing treatments. METHOD: English data were obtained from Google Scholar, PubMed, Scopus, and Cochrane library studies published between 1990-December 2022. RESULT: Inhibitors of the LRRK2 pathway can be considered as the novel treatment approaches for IBD and PD treatment. CONCLUSION: Common mediators and pathways are involved in the pathophysiology of IBD and PD, which are majorly correlated with inflammatory situations. Such diseases could be used for further clinical investigations.

Spinal Muscular Atrophy Treatment: The MTOR Regulatory Intervention.

Spinal muscular atrophy (SMA) is a hereditary disorder affecting neurons and muscles, resulting in muscle weakness and atrophy. Most SMA cases are diagnosed during infancy or early childhood, the most common inherited cause of infant mortality without treatment. Still, SMA might appear at older ages with milder symptoms. SMA patients demonstrate progressive muscle waste, movement problems, tremors, dysphagia, bone and joint deformations, and breathing difficulties. The mammalian target of rapamycin (mTOR), the mechanistic target of rapamycin, is a member of the phosphatidylinositol 3-kinase-related kinase family of protein kinases encoded by the mTOR gene in humans. The mTOR phosphorylation, deregulation, and autophagy have shown dissimilarity amongst SMA cell types. Therefore, exploring the underlying molecular process in SMA therapy could provide novel insights and pave the way for finding new treatment options. This paper provides new insight into the possible modulatory effect of mTOR/ autophagy in SMA management.

TLR/mTOR inflammatory signaling pathway: novel insight for the treatment of schizophrenia.

The Toll-like receptor (TLR)/mammalian target of rapamycin (mTOR) signaling pathway is involved in the intracellular regulation of protein synthesis, specifically the ones that mediate neuronal morphology and facilitate synaptic plasticity. The activity of TLR/mTOR signaling has been disrupted, leading to neurodevelopment and deficient synaptic plasticity, which are the main symptoms of schizophrenia. The TLR receptor activates the mTOR signaling pathway and increases the elevation of inflammatory cytokines. Interleukin (IL)-6 is the most commonly altered cytokine, while IL-1, tumor necrosis factor, and interferon (IFN) also lead to SCZ. Anti-inflammatory and anti-oxidative agents such as celecoxib, aspirin, minocycline, and omega-3 fatty acids have shown efficiency against SCZ. As a result, inhibition of the inflammatory process could be suggested for the treatment of SCZ. So mTOR/TLR blockers represent the treatment of SCZ due to their inflammatory consequences. The objective of the present work was to find a novel anti-inflammatory agent that may block the mTOR/TLR inflammatory signaling pathways and might pave the way for the treatment of neuroinflammatory SCZ. Data were collected from experimental and clinical studies published in English between 1998 and October 2022 from Google Scholar, PubMed, Scopus, and the Cochrane library.

Kynurenine pathway and its role in neurologic, psychiatric, and inflammatory bowel diseases.

Tryptophan metabolism along the kynurenine pathway is of central importance for the immune function. It prevents hyperinflammation and induces long-term immune tolerance. Accumulating evidence also demonstrates cytoprotective and immunomodulatory properties of kynurenine pathway in conditions affecting either central or peripheral nervous system as well as other conditions such as inflammatory bowel disease (IBD). Although multilevel association exists between the inflammatory bowel disease (IBD) and various neurologic (e.g., neurodegenerative) disorders, it is believed that the kynurenine pathway plays a pivotal role in the development of both IBD and neurodegenerative disorders. In this setting, there is strong evidence linking the gut-brain axis with intestinal dysfunctions including IBD which is consistent with the fact that the risk of neurodegenerative diseases is higher in IBD patients. This review aims to highlight the role of kynurenine metabolic pathway in various neurologic and psychiatric diseases as well as relationship between IBD and neurodegenerative disorders in the light of the kynurenine metabolic pathway.

Wharton's jelly mesenchymal stem cells attenuate global hypoxia-induced learning and memory impairment via preventing blood-brain barrier breakdown.

Objectives: Intracerebroventricular (ICV) injections of mesenchymal stem cells (MSCs) may improve the function and structure of blood-brain barrier (BBB), possibly by preserving the BBB integrity. This study examined the impact of Wharton's jelly (WJ)-MSCs on cognitive dysfunction and BBB disruption following a protracted hypoxic state. Materials and Methods: Twenty-four male Wistar rats were randomly studied in four groups: Control (Co): Healthy animals, Sham (Sh): Rats were placed in the cage without hypoxia induction and with ICV injection of vehicle, Hypoxic (Hx)+vehicle: Hypoxic rats with ICV injection of vehicle (5 µl of PBS), and Hx+MSCs: Hypoxic rats with ICV injection of MSCs. Spatial learning and memory were evaluated one week after WJ-MSCs injection, and then animals were sacrificed for molecular research. Results: Hypoxia increased latency and lowered the time and distance required reaching the target quarter, according to the findings. Furthermore, hypoxic rats had lower gene expression and protein levels of hippocampus vascular endothelial (VE)-cadherin, claudin 5, and tricellulin gene expression than Co and Sh animals (P<0.05). Finally, administering WJ-MSCs after long-term hypoxia effectively reversed the cognitive deficits and prevented the BBB breakdown via the upregulation of VE-cadherin, claudin 5, and tricellulin genes (P<0.05). Conclusion: These findings suggest that prolonged hypoxia induces spatial learning and memory dysfunction and increases BBB disruption, the potential mechanism of which might be via reducing VE-cadherin, claudin 5, and tricellulin genes. Hence, appropriate treatment with WJ-MSCs could reverse ischemia adverse effects and protect the BBB integrity following prolonged hypoxia.

Therapeutic potential of infliximab for pruritus in mice model of cholestasis induced by bile duct ligation: Possible involvement of IL-31.

BACKGROUND: Cholestatic pruritus is a distressful sensation that can cause a massive desire of scratching skin. Despite maximum medication therapy, some patients still experience pruritus. In this study, we evaluated the effect of infliximab on cholestatic pruritus induced in mice by bile duct ligation. METHODS: Twenty-four balb/c mice were randomly assigned to three groups; sham, control, and treatment. The bile duct ligation procedure was performed on mice in the control and treatment groups. After six days, mice in the treatment group received subcutaneous administration of infliximab, and the next day all mice were subjected to the scratching behavior test. Skin, dorsal root ganglia (DRG), and blood samples of mice were collected and evaluated by histopathological, molecular, and biochemical tests. RESULTS: The scratching behavior has significantly decreased in mice with cholestasis after the administration of infliximab. The levels of TNFα, TNFR1, TNFR2, NF-κB, and IL-31were higher in control mice compared to sham. In addition, expression levels of TNFR1, NF-κB, and IL-31 were decreased in the treatment group compared to the controls in skin and DRG, while TNFR2 levels were decreased only in DRG. CONCLUSION: Infliximab can block TNFα interaction with receptors and inhibit further inflammatory response. Also, our results suggested that infliximab can suppress IL-31 expression indirectly, which is a well-known cytokine in pruritus pathophysiology Infliximab can be a potential therapeutic approach in resistant pruritus in cholestatic disorders.

Statins: Beneficial Effects in Treatment of COVID-19.

The recent viral disease COVID-19 has attracted much attention. The disease is caused by SARS-CoV-19 virus which has different variants and mutations. The mortality rate of SARS-CoV-19 is high and efforts to establish proper therapeutic solutions are still ongoing. Inflammation plays a substantial part in the pathogenesis of this disease causing mainly lung tissue destruction and eventually death. Therefore, anti-inflammatory drugs or treatments that can inhibit inflammation are important options. Various inflammatory pathways such as nuclear factor Kappa B (NF-κB), signal transducer of activators of transcription (STAT), nod-like receptor family protein 3 (NLRP), toll-like receptors (TLRs), mitogen-activated protein kinase (MAPK), and mammalian target of rapamycin (mTOR) pathways and mediators, such as interleukin (IL)-6, IL-1ß, tumor necrosis factor-α (TNF-α), and interferon-γ (INF-γ), cause cell apoptosis, reduce respiratory capacity and oxygen supply, eventually inducing respiratory system failure and death. Statins are well known for controlling hypercholesterolemia and may serve to treat COVID-19 due to their pleiotropic effects among which are anti-inflammatory in nature. In this chapter, the anti-inflammatory effects of statins and their possible beneficial effects in COVID-19 treatment are discussed. Data were collected from experimental and clinical studies in English (1998-October 2022) from Google Scholar, PubMed, Scopus, and the Cochrane Library.

Orexin receptor antagonists in the pathophysiology and treatment of sleep disorders and epilepsy.

The correlation between sleep and epilepsy has been argued over the past decades among scientists. Although the similarities and contrasts between sleep and epilepsy had been considered, their intertwined nature was not revealed until the nineteenth century. Sleep is recognized as a recurring state of mind and body through alternating brain electrical activities. It is documented that sleep disorders are associated with epilepsy. The origin, suppression, and spread of seizures are affected by sleep. As such, in patients with epilepsy, sleep disorders are a frequent comorbidity. Meanwhile, orexin, a wake-promoting neuropeptide, provides a bidirectional effect on both sleep and epilepsy. Orexin and its cognate receptors, orexin receptor type 1 (OX1R) and type 2 (OX2R), orchestrate their effects by activating various downstream signaling pathways. Although orexin was considered a therapeutic target in insomnia shortly after its discovery, its potential usefulness for psychiatric disorders and epileptic seizures has been suggested in the pre-clinical studies. This review aimed to discuss whether the relationship between sleep, epilepsy, and orexin is clearly reciprocal.

IDO/Kynurenine; novel insight for treatment of inflammatory diseases.

Inflammation and oxidative stress play pivotal roles in pathogenesis of many diseases including cancer, type 2 diabetes, cardiovascular disease, atherosclerosis, neurological diseases, and inflammatory diseases such as inflammatory bowel disease (IBD). Inflammatory mediators such as interleukins (ILs), interferons (INF-s), and tumor necrosis factor (TNF)-α are related to an extended chance of inflammatory diseases initiation or progression due to the over expression of the nuclear factor Kappa B (NF-κB), signal transducer of activators of transcription (STAT), nod-like receptor family protein 3 (NLRP), toll-like receptors (TLR), mitogen-activated protein kinase (MAPK), and mammalian target of rapamycin (mTOR) pathways. These pathways are completely interconnected. Theindoleamine 2,3 dioxygenase (IDO) subset of the kynurenine (KYN) (IDO/KYN), is a metabolic inflammatory pathway involved in production of nicotinamide adenine dinucleotide (NAD + ). It has been shown that IDO/KYN actively participates in inflammatory processes and can increase the secretion of cytokines that provoke inflammatory diseases. Data were extracted from clinical and animal studies published in English between 1990-April 2022, which were collected from PubMed, Google Scholar, Scopus, and Cochrane library. IDO/KYN is completely associated with inflammatory-related pathways, thus leading to the production of cytokines such as TNF-α, IL-1ß, and IL-6, and ultimately development and progression of various inflammatory disorders. Inhibition of the IDO/KYN pathway might be a novel therapeutic option for inflammatory diseases. Herein, we gathered data on probable interactions of the IDO/KYN pathway with induction of some inflammatory diseases.

Therapeutic potential of bromhexine for acute itch in mice: Involvement of TMPRSS2 and kynurenine pathway.

Itching is an unpleasant sensation on the skin that could negatively impact the quality of life. Over the years, many non-pharmacological and pharmacological approaches have been introduced to mitigate this burdensome condition; However, the effectiveness of these methods remains questioned. Bromhexine, derived from the Adhatoda vasica plant, is a safe drug with minimal side effects. It has been widely used in managing respiratory symptoms over the years. The results of our study revealed that bromhexine has the potential to alleviate acute itch induced by Compound 48/80, a known mast cell destabilizer. According to our findings, bromhexine exerts its antipruritic effects primarily by inhibiting the Transmembrane Protein Serine Protease 2 (TMPRSS2) and, to a lesser extent, by decreasing the activation of the Kynurenine Pathway (KP). We further investigated the KP involvement by administrating 1-Methyl Tryptophan (1-MT), a known indoleamine-2,3-dioxygenase (IDO) inhibitor. 1-MT was found to be effective in reducing the itch itself. Moreover, co-administration of bromhexine and 1-MT resulted in synergistic antipruritic effects, suggesting that KP plays a role in acute itch. To conclude, we have presented for the first time a repositioning of bromhexine as a treatment for acute itch. In addition, we addressed the involvement of TMPRSS2 and KP in this process.

Cannabidiol Improves Random-Pattern Skin Flap Survival in Rats: Involvement of Cannabinoid Type-2 Receptors.

BACKGROUND: One of the major complications associated with random-pattern skin flaps is distal necrosis. Cannabidiol (CBD) has recently gained much attention as a therapeutic anti-inflammatory agent. We aimed to evaluate the efficacy of CBD on the random-pattern skin flap survival (SFS) in rats and to explore the possible involvement of cannabinoid type-2 (CB2) receptors. METHODS: In this controlled experimental study, we randomly divided male Wistar rats into seven study groups (six rats each). We performed a random-pattern skin flap model in each rat following pretreatment with vehicle (control) or multiple doses of CBD (0.3, 1, 5, or 10 mg/kg). In a separate group, we injected SR144528 (2 mg/kg), a high affinity and selective CB2 inverse agonist, before the most effective dose of CBD (1 mg/kg). A sham nontreated and nonoperated group was also included. Seven days after surgeries, the percentage of necrotic area (PNA) was calculated. Histopathological microscopy, CB2 expression level, and interleukin (IL)-1ß and tumor necrosis factor (TNF)-α concentrations were also investigated in the flap tissue samples. RESULTS: A PNA of 72.7 ± 7.5 (95% confidence interval [CI]: 64.8-80.6) was captured in the control group. Following treatment with CBD 0.3, 1, 5, and 10 mg/kg, a dose-dependent effect was observed with PNAs of 51.0 ± 10.0 (95% CI: 40.5-61.5; p <0.05), 15.4 ± 5.8 (95% CI: 9.3-21.5; p <0.001), 37.1 ± 10.2 (95% CI: 26.3-47.8; p <0.001), and 46.4 ± 14.0 (95% CI: 31.7-61.1; p <0.001), respectively. Histopathologically, tissues enhanced significantly. Besides, CB2 expression surged remarkably, IL-1ß and TNF-α concentrations decreased considerably after treatment with CBD of 1 mg/kg compared with the control (p <0.05 and <0.001, respectively). Administering SR144528 reversed the favorable effects of CBD of 1 mg/kg, both macroscopically and microscopically. CONCLUSION: Pretreatment with CBD of 1 mg/kg improved SFS considerably in rats and exerted desirable anti-inflammatory effects which were possibly mediated by CB2 receptors.

The Possible Protective Effects of Ondansetron and Tropisetron on Optic Nerve Crush Injury in Rats.

BACKGROUND: This study aimed to evaluate the potential neuroprotective effect of cyclosporine - a calcineurin inhibitor-, ondansetron, and tropisetron-5-hydroxytryptamine (serotonin) 3 receptor (5-HT3R) antagonists-, on optic nerve crush (ONC) injury in rats. Moreover, underlying signaling activities of their beneficial neuroprotective effects were studied. METHODS: Adult male rats were treated with the intravitreal administration of cyclosporine (1.6 mM), ondansetron (100 nM), and tropisetron (100 nM) immediately after the induction of ONC. Subsequently, on 7th day after surgery, the rats' retinas were extracted, and the expression of apoptotic regulators (Bax and Bcl-2) and calcineurin were studied by western blot analysis. RESULTS: The induction of ONC injury was associated to higher expression of Bax and calcineurin, while Bcl-2 expression was considerably decreased in these animals. Intravitreal treatment with cyclosporine (1.6 mM), ondansetron (100 nM), and tropisetron (100 nM) significantly attenuated the increased expression of Bax and calcineurin. Moreover, the treatment with these agents resulted in an elevated expression of Bcl-2 in the retina. CONCLUSION: Our findings indicate that cyclosporine, ondansetron, and tropisetron protect against ONC injury in rats, possibly via the suppression of apoptosis and modulation of calcineurin activity directly and via 5-HT3 receptors. Moreover, immunoblotting showed that tropisetron was more effective as opposed to ondansetron. Further studies are needed to evaluate the precise mechanism behind cyclosporine, ondansetron, and tropisetron activities.

Neuroprotective effects of Lasmiditan and Sumatriptan in an experimental model of post-stroke seizure in mice: Higher effects with concurrent opioid receptors or KATP channels inhibitors.

BACKGROUND: Early post-stroke seizure frequently occurs in stroke survivors within the first few days and is associated with poor functional outcomes. Therefore, efficient treatments of such complications with less adverse effects are pivotal. In this study, we investigated the possible beneficial effects of lasmiditan and sumatriptan against post-stroke seizures in mice and explored underlying mechanisms in their effects. METHODS: Stroke was induced by double ligation of the right common carotid artery in mice. Immediately after the ligation, lasmiditan (0.1 mg/kg, intraperitoneally [i.p.]) or sumatriptan (0.03 mg/kg, i.p.) were administered. Twenty-four hours after the stroke induction, seizure susceptibility was evaluated using the pentylenetetrazole (PTZ)-induced clonic seizure model. In separate experiments, naltrexone (a non-specific opioid receptor antagonist) and glibenclamide (a KATP channel blocker) were administered 15 min before lasmiditan or sumatriptan injection. To evaluate the underlying signaling pathways, ELISA analysis of inflammatory cytokines (TNF-α and IL-1ß) and western blot analysis of anti- and pro-apoptotic markers (Bcl-2 and Bax) were performed on mice isolated brain tissues. RESULTS: Lasmiditan (0.1 mg/kg, i.p.) and sumatriptan (0.03 mg/kg, i.p.) remarkably decreased seizure susceptibility in stroke animals by reducing inflammatory cytokines and neuronal apoptosis. Concurrent administration of naltrexone (10 mg/kg, i.p.) or glibenclamide (0.3 mg/kg, i.p.) with lasmiditan or sumatriptan resulted in a higher neuroprotection against clonic seizures and efficiently reduced the inflammatory and apoptotic markers. CONCLUSION: Lasmiditan and sumatriptan significantly increased post-stroke seizure thresholds in mice by suppressing inflammatory cytokines and neuronal apoptosis. Lasmiditan and sumatriptan seem to exert higher effects on seizure threshold with concurrent administration of the opioid receptors or KATP channels modulators.

A comprehensive insight into the anti-inflammatory properties of dapsone.

The 4,4'-diaminodiphenyl sulfone (DDS), also known as dapsone, is traditionally used as a potent anti-bacterial agent in clinical management of leprosy. For decades, dapsone has been among the first-line medications used in multidrug treatment of leprosy recommended by the World Health Organization (WHO). Shortly after dapsone's discovery as an antibiotic in 1937, the dual function of dapsone (anti-microbial and anti-inflammatory) was elucidated. Dapsone exerts its anti-bacterial effects by inhibiting dihydrofolic acid synthesis, leading to inhibition of bacterial growth, while its anti-inflammatory properties are triggered by inhibiting reactive oxygen species (ROS) production, reducing the effect of eosinophil peroxidase on mast cells and downregulating neutrophil-mediated inflammatory responses. Among the leading mechanisms associated with its anti-microbial/anti-protozoal effects, dapsone clearly has multiple antioxidant, anti-inflammatory, and anti-apoptotic functions. In this regard, it has been described in treating a wide variety of inflammatory and infectious skin conditions. Previous reports have explored different molecular targets for dapsone and provided insight into the anti-inflammatory mechanism of dapsone. This article reviews several basic, experimental, and clinical approaches on anti-inflammatory effect of dapsone.

Pentylenetetrazole preconditioning attenuates severity of status epilepticus induced by lithium-pilocarpine in male rats: evaluation of opioid/NMDA receptors and nitric oxide pathway.

BACKGROUND: Non-deleterious episodes of seizure preconditioning can efficiently increase the brain's resistance to the consequent severe status epilepticus (SE). In the present investigation, we intended to elucidate further (i) the effects of preconditioning with pentylenetetrazole (PTZ) in the lithium-pilocarpine model of SE in male rats, along with (ii) the possible contribution of opioid, N-Methyl-D-aspartate (NMDA) receptors, and nitric oxide (NO) signaling transduction. METHODS: In male Wistar rats, the SE was incited by lithium administration (127 mg/kg, ip) 20 h before pilocarpine (60 mg/kg, ip). PTZ preconditioning was induced via a low-dose injection of PTZ (25 mg/kg) for 5 repeated days. To investigate the underlying signaling pathway, naltrexone (NTX; a non-specific opioid receptor antagonist), MK-801 (NMDA antagonist), L-NAME (a non-specific nitric oxide synthase (NOS) inhibitor), aminoguanidine (AG; a specific inducible NOS inhibitor), and 7-Nitroindazole (7-NI; a specific neuronal NOS inhibitor) were administered 15 min before PTZ injection. RESULTS: Preconditioning with PTZ successfully ameliorates the increased SE scores due to lithium-pilocarpine-induced SE (p < 0.05). None of the drugs given without PTZ preconditioning had an impact on SE outcomes. The observed anti-convulsant effect of PTZ preconditioning is reversed by the opioid receptor antagonists and NOS inhibitors. Conversely, the NMDA receptor antagonist enhanced the anti-convulsion activity caused by PTZ preconditioning. Quantifying nitrite level in the hippocampus showed a significant NO level decline in the PTZ-preconditioned animals. CONCLUSIONS: Therefore, PTZ preconditioning generates endogenous protection against SE, possibly through targeting opioid/NMDA receptors and NO signaling transduction in the animal model of lithium-pilocarpine-induced SE.

Buspirone Ameliorates Colon Inflammation in TNBS-Induced Rat Acute Colitis: The Involvement of TLR4/NF-kB Pathway.

Inflammatory bowel disease (IBD) is an inflammatory situation involving the whole digestive system. This illness includes ulcerative colitis and Crohn's disease. According to scientific research, the immune system plays an essential part in developing this disease. Recently, buspirone has been discovered to have anti-inflammatory properties. As a result, this research aims to see if buspirone provides anti-inflammatory effects in a rat model of TNBS-induced colitis. Control, TNBS, dexamethasone (2 mg/kg), and buspirone (5, 10, and 20 mg/kg) were randomly given to six groups of 36 male Wistar rats. Colitis was induced by intrarectal instillation of TNBS in all research groups except the control group, and rats were meliorated with dexamethasone and buspirone. Macroscopic and microscopic lesions appeared after colitis induction, while therapy with dexamethasone and buspirone significantly improved the lesions. TLR4 and pNF-κB expression were also enhanced during colitis induction. On the other hand, the administration of dexamethasone or buspirone resulted in a considerable reduction in their expression. Tissue TNF-α and MPO activity were enhanced after induction of colitis in terms of biochemical variables; however, administration of dexamethasone or buspirone reduced TNF-α and MPO activity. Eventually, in an animal model of severe colitis, buspirone displayed anti-inflammatory characteristics via lowering the TLR4/NF-ĸB signaling pathway's activity in an animal model of acute colitis.

Protective Effects of Dapsone on Scopolamine-Induced Memory Impairment in Mice: Involvement of Nitric Oxide Pathway.

Introduction: The leading cause of memory impairment is dementia-related disorders. Since current treatments for memory impairment target the neuroinflammatory pathways, we selected dapsone, an anti-inflammatory agent, to evaluate its effects on scopolamine-induced memory impairment in mice and the underlying role of nitric oxide (NO). Methods: Scopolamine (1 mg/kg, intraperitoneal [i.p.]) was used for induction of memory impairment. The animals received various doses of dapsone (0.1, 0.3, 1, 5, and 10 mg/kg, i.p.). Duration and number of arms visits in the Y-maze and step-through latency in the passive-avoidance were documented. To evaluate the underlying signaling pathway, N(ω)-nitro-L-arginine methyl ester (a nonspecific NO synthase [NOS] inhibitor), aminoguanidine (a specific inducible NOS inhibitor), and 7-nitroindazole (a specific neuronal NOS inhibitor) were administered 30 min after dapsone administration. Results: Dapsone (5 mg/kg) substantially improved memory acquisition in scopolamine-induced memory impairment. Additionally, NOS inhibitors considerably reversed the observed neuroprotective effects of dapsone, accompanied by the elevation of NO levels. Conclusion: Dapsone revealed a neuroprotective effect against scopolamine-induced memory impairment in mice, possibly through the nitrergic pathway.

The possible role of nitric oxide signaling and NMDA receptors in allopurinol effect on maximal electroshock- and pentylenetetrazol-induced seizures in mice.

Allopurinol, a uric-acid-lowering medication, has shown its efficacy in several studies suggesting that allopurinol can be prescribed as adjunctive cure meant for intractable epilepsy. The exact mechanism of allopurinol is still unknown. This study evaluates allopurinol's effect on seizure threshold, seizure incidence, and mortality rate in mice models. Moreover, the possible involvement of nitric oxide (NO) pathway and N-methyl-D-aspartate (NMDA) receptors are investigated. To evaluate the effect of allopurinol on seizure, we used the pentylenetetrazole (PTZ)-induced seizure along with maximal electroshock (MES)-induced seizure. To assess the underlying mechanism behind the allopurinol activity, we used nitric oxide synthase (NOS) substrate (L-arginine), NOS inhibitors (L-NAME, aminoguanidine, 7-nitroindazole), and NMDA receptor antagonist (MK-801). Intraperitoneal allopurinol administration at a dose of 50 mg/kg in mice showed a significant (p < 0.001) anti-convulsant activity in the PTZ-induced seizure. Even though pre-treatment with L-Arginine (60 mg/kg) potentiates allopurinol's anti-convulsant effect in the PTZ-induced seizure, pre-treatment with L-NAME (10 mg/kg), aminoguanidine (100 mg/kg), and 7-nitroindazole (30 mg/kg) reversed the anti-convulsant effect of allopurinol in the PTZ-induced seizure. In addition, pre-treatment with MK-801 also decreased the anti-convulsant effect of allopurinol in the PTZ-induced seizure. While allopurinol at a dose of 50 mg/kg and 100 mg/kg did not induce protection against seizure incidence in the MES-induced seizure, it revealed a remarkable effect in reducing the mortality rate in the MES-induced seizure. Allopurinol increases the seizure threshold in PTZ-induced seizure and enhances the survival rate in MES-induced seizure. Allopurinol exerts its anti-convulsant effect, possibly through targeting NO pathway and NMDA receptors.

Modafinil exerts anticonvulsive effects against lithium-pilocarpine-induced status epilepticus in rats: A role for tumor necrosis factor-α and nitric oxide signaling.

BACKGROUND: Status epilepticus (SE) is a continuous episode of seizures which leads to hippocampal neurodegeneration, severe systemic inflammation, and extreme damage to the brain. Modafinil, a psychostimulant and wake-promoting agent, has exerted neuroprotective and anti-inflammatory effects in previous preclinical studies. The aim of this study was to assess effects of modafinil on the lithium-pilocarpine-induced SE rat model and to explore possible involvement of tumor necrosis factor-α (TNF-α) and nitric oxide (NO) pathways in this regard. METHODS: Status epilepticus was provoked by injection of lithium chloride (127 mg/kg, intraperitoneally [i.p]) and pilocarpine (60 mg/kg, i.p.) in rats. Animals received different modafinil doses (50, 75, 100, and 150 mg/kg, i.p.) and SE scores were documented over 3 hours of duration. Moreover, the role of the nitrergic pathway in the effects of modafinil was evaluated by injection of the non-selective NO synthase (NOS) inhibitor L-NG-Nitro arginine methyl ester (L-NAME, 10 mg/kg, i.p.), the selective neuronal NOS inhibitor 7-nitroindazole (30 mg/kg, i.p.), and the selective inducible NOS inhibitor aminoguanidine (100 mg/kg, i.p.) 15 min before saline/vehicle or modafinil. The ELISA method was used to quantify TNF-α and NO metabolite levels in the isolated hippocampus. RESULTS: Modafinil at 100 mg/kg significantly decreased SE scores (P < 0.01). Pre-treatment with L-NAME, 7-nitroindazole, and aminoguanidine significantly reversed the anticonvulsive effects of modafinil. Status epilepticus-induced animals showed significantly higher NO metabolite and TNF-α levels in their hippocampal tissues, an effect that was reversed by modafinil (100 mg/kg, i.p.) treatment. Administration of NOS inhibitors resulted in excessive NO level reduction but an escalation of TNF-α level in modafinil-treated SE-animals. CONCLUSION: Our study revealed anticonvulsive effects of modafinil in the lithium-pilocarpine-induced SE rat model via possible involvement of TNF-α and nitrergic pathways.